Norm of Tularemia Skin Test
Negative. No redness, induration, or wheal.
Current or past infection with Francisella tularensis.
Normal finding. May also occur the first few days after infection.
Description of Tularemia Skin Test
See Tularemia agglutinins—Serum for a description of the infectious disease of tularemia. The Foshay skin test for tularemia is based on a delayed hypersensitivity reaction. Results will be positive for clients with current infection of at least 7 days or for up to 5 years after recovery.
Professional Considerations of Tularemia Skin Test
Consent form NOT required.
- Obtain a 4-mL syringe with an intradermal needle and purified F. tularensis antigen.
- Cleanse the forearm site for injection with an alcohol wipe and allow the area to dry.
- Inject F. tularensis antigen, derived from culture, intradermally.
- Record the site of injection.
- Inspect the injection site in 48 hours. Reaction is positive if redness and induration of >5 mm diameter are present at the site.
- Let the site air-dry.
Client and Family Teaching
- If routinely handling wild animals (such as skinning rabbits), wear gloves and goggles during contact, and thoroughly cook any wild animal meat to be ingested.
- Return in 48 hours to have the injection site viewed and the skin test interpreted.
Factors That Affect Results
- False-negative results may occur during the first week after infection as a result of insufficient antibody formation. If tularemia is suspected, the test should be repeated in 1 week.
- If serum testing for tularemia agglutinins is to be done, it should be performed before this test.